Associated Press

Russia's Maria Sharapova serves the ball to China's Zheng Jie during their third round match of the French Open tennis tournament at the Roland Garros stadium Saturday, June 1, 2013 in Paris. (AP Photo/Michel Spingler)

PARIS — A frowning Maria Sharapova walked toward the net, peering at a mark on the other side and trying to argue her way out of yet another double-fault.

"It hit the outside line," she told the chair umpire.

He disagreed — incorrectly — but Sharapova wasn't fazed for long. She overcame eight double-faults, the erroneous ruling and a second-set deficit to beat Zheng Jie 6-1, 7-5 in the third round Saturday at the French Open.

"I'm happy with the way I fought back and I found a way to win," said Sharapova, who completed a career Grand Slam by winning the Roland Garros title last year.

Seven-time champion Rafael Nadal had to come from behind yet again and reached the fourth round by beating Fabio Fognini 7-6 (5), 6-4, 6-4. After dropping the opening set in his first two matches, Nadal trailed 4-2 and was down a break at 6-5 before surging ahead for his 18th consecutive victory.

Nadal seeks to become first man to win eight titles at the same Grand Slam event. He next plays No. 13-seeded Kei Nishikori, who became the first Japanese man in 75 years to reach the fourth round at Roland Garros, beating Benoit Paire 6-3, 6-7 (3), 6-4, 6-1.

Sharapova will next play Sloane Stephens of the United States, who reached the fourth round for the second consecutive year by beating Marina Erakovic 6-4, 6-7 (5), 6-3.